//字符串反转
package main
import "fmt"
func reverse(str string) string {
    var result string
    strLen := len(str)
    for i := 0; i < strLen; i++ {
        result = result + fmt.Sprintf("%c", str[strLen-i-1])
    }
    return result
}
func reverse1(str string) string {
    var result []byte
    tmp := []byte(str)
    length := len(str)
    for i := 0; i < length; i++ {
        result = append(result, tmp[length-i-1])
    }
    return string(result)
}
func main() {
    var str1 = "hello"
    str2 := "world"
    str3 := fmt.Sprintf("%s %s", str1, str2)
    n := len(str3)
    fmt.Println(str3)
    fmt.Printf("len(str3)=%d\n", n)
    substr := str3[0:5]
    fmt.Println(substr)
    substr = str3[6:]
    fmt.Println(substr)
    result := reverse(str3)
    fmt.Println(result)
    result = reverse1(result)
    fmt.Println(result)
}字符串练习
package main
import (
    "fmt"
)
func testString() {
    var str = "hello"
    fmt.Printf("str[0]=%c len(str)=%d\n", str[0], len(str))
    for index, val := range str {
        fmt.Printf("str[%d]=%c\n", index, val)
    }
    //str[0] = '0'
    //fmt.Println("after modify:", str)
    var byteSlice []byte
    byteSlice = []byte(str)
    byteSlice[0] = '0'
    str = string(byteSlice)
    fmt.Println("after modify:", str)
    fmt.Printf("len(str)=%d\n", len(str))
    str = "hello, 少林之巅"
    fmt.Printf("len(str)=%d\n", len(str))
    str = "中问123"
    fmt.Printf("last:len(str)=%d\n", len(str))
    var b rune = '中'
    fmt.Printf("b=%c\n", b)
    var runeSlice []rune
    runeSlice = []rune(str)
    fmt.Printf("str 长度:%d, len(str)=%d\n", len(runeSlice), len(str))
}
func testReverseStringV1() {
    var str = "hello中文 "
    var bytes []byte = []byte(str)
    for i := 0; i < len(str)/2; i++ {
        tmp := bytes[len(str)-i-1]
        bytes[len(str)-i-1] = bytes[i]
        bytes[i] = tmp
    }
    str = string(bytes)
    fmt.Println(str)
}
func testReverseStringV2() {
    var str = "hello中文 "
    var r []rune = []rune(str)
    for i := 0; i < len(r)/2; i++ {
        tmp := r[len(r)-i-1]
        r[len(r)-i-1] = r[i]
        r[i] = tmp
    }
    str = string(r)
    fmt.Println(str)
}
func testHuiWen() {
    var str = "上海自来水来自海上"
    var r []rune = []rune(str)
    for i := 0; i < len(r)/2; i++ {
        tmp := r[len(r)-i-1]
        r[len(r)-i-1] = r[i]
        r[i] = tmp
    }
    str2 := string(r)
    if str2 == str {
        fmt.Println(str, " is huiwen")
    } else {
        fmt.Println(str, " is not huiwen")
    }
}
func main() {
    //testString()
    //testReverseStringV2()
    testHuiWen()
}